Improvement in qrind



G.\M.LIBBEV.

Grinding Machines.

No. 134,296. Patented Dec124,1872.

@ aubjrr p W AM PHOTO-LITHOGRAPHIC CA7. Nf/CSEORNES PROCESS GEORGE W.LIBBEY, OF PHILADELPHIA, PENNSYLVANIA.

lhlPRQVEWEENT IN GRlNfiltG-EWACl-HNES.

Specification forming part of Letters Patent No. 1$1,2, dated December21, 1872.

To all whom it may concern:

Be it known that I, GEORGE W. LIBBEY, of the city and county ofPhiladelphia and State of Pennsylvania, have invented an ImprovedGrinding-Machine, of which the following is a specification:

My invention relates to that class of grinding-machines in which arevolving grindstone or other grinding-disk is employed; and myinvention consists in combining with the reciprocating rest of themachine a flexible guidebar, by the adjustment of which a straight orcurved cutting-edge may be imparted to a plane-iron, chisel, or othercutting instrument. My invention also consists of a reciprocating rest,constructed in the peculiar manner fully described hereafter, forpresenting the tool to the grinding-disk.

Figure 1 is a side view, partly in section, of my improvedgrinding-machine; Fig. 2, a vertical section of part of Fig. 1; Fig. 3,a plan view; and Fig. 4, a plan view of part of the machine.

A and A are the opposite side-frames of the machine, and to suitablebearings in these frames is adapted a shaft, B, which may be driven byhand, or through the medium of a treadle, by the foot, or by power, acog-wheel, E, on the driving-shaft gearing into a pinion, F, on shaft1), which also turns in the opposite frames, and which carries thegrindingdisk Gr.

The frame A is constructed to serve as a shield for the wheel and pinionfor the prevention of accidents, (see Fig. 1,) and for the sake ofeconomy and uniformity the frame A is of similar construction.

The frames are connected together by a cross-bar, H, to which issecured, by three set-screws, d, d, and c, a flexible bar, I, the upperand lower edges of the latter being adapted to grooves in the armsf f ofthe sliding bracket J, to which is hinged, at the point an, a plate, K,the inclination of this plate being determined by a screw, L, passingthrough a swivel-nut, b, on the sliding bracket, and

connected to a coupling, a, jointed to the said plate K.

A reciprocating motion is imparted to the sliding bracket and itsadjuncts by means of the crank M and connecting-rod N, the former beingsecured to a shaft, P, turning in suitable hearings in the frame A, thisshaft deriving its rotating motion from the driving-shaft 13 through themedium of the bevel-pinion h and bevel-wheel i. The course in which thesliding bracket J reciprocates will depend upon the adjustment of theflexible guide-bar I. If this bar, by turning the screw 0, be permittedto bear throughout its whole length against the fixed cross-bar H, whichis straight, then the bracket will reciprocate in astraight course; butif the flexible bar be adjusted to the curved shape shown in Fig. 4.,then the bracket will reciprocate in a correspondingly curved course.

In sharpening the blade of a jack-plane, for instance, which has to berounded on the edge, the flexible bar I is adjusted to a correspondingcurve, and the blade is secured to the plate K by means of a set-screw,3 passing through the usual hole in the blade, the plate being in thefirst instance elevated, and being gradually depressed bymanipulatingthe screw L, while the cutting-edge of the reciprocatingblade is caused to bear against the periphery of the grinding-disk Gr,this depression of the plate and blade being continued until the latterhas been reduced to the desired extent, and has the proper bevelimparted to it.

WVhen the blade of a truing-plane or a paring-chisel has to besharpened, the flexible bar is so adjusted as to be straight, in whichcase the result will be the imparting of a straight cutting-edge to theblade.

Many difierentcutting-tools may be sharpened and may have straight orcurved cutting-edges imparted to them, as desired, by the machine,suitable appliances demanded by the nature of the tool being employedfor securing it to the plate K. A concave edge may, if desired, beimparted to a blade or cutter, it the flexible bar be adjustedaccordingly.

I claim as my invention- 1. A grinding-machine in which a reciprocatingrest is combined with a flexible and adjustable guide-bar, substantiallyin the manner described.

2. The combination, with a grindstone, substantially as described, ofthe reciprocating bracket, the plate K hinged to the same, and the screwL, hinged swivel a, and self-accommodating not b.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEORGE W. LIBBEY.

Witnesses:

WM. A. STEEL, JOHN K. BUrER'rUs.

